 
 
 
27.12.8  Orthogonal projection in space
See Section 26.14.8 for projections in the plane.
The projection
command creates a projection.
- 
projection takes one mandatory argument and one
optional argument:
- 
O, a geometrix object.
- Optionally, P, a point.
 
- projection(O) returns a new command which projects
points onto O.
- projection(O,P) returns and draws the projection of
P onto O.
Examples
| P:=point(0,0,1);
 p1:=projection(line(point(0,0,0),point(1,1,1)));
 coordinates(p1(P)) | 
which is the projection of (0,0,1) onto the line.
| coordinates(projection(plane(point(1,0,0),point(0,0,0),point(1,1,1)),point(0,0,1))) | 
which is the projection of the point (0,0,1) onto the plane.
 
 
